A man walks down the street holding a lobster.
"What you doing?" his friend asks.
"I'm going to have the lobster for lunch."
The lobster pipes up, "No thanks. I've already eaten.This joke does not work in Bosnian because you use one preposition, za, if something is going to be lunch and a different preposition, na, if someone (or something) is joining you for lunch.
Prepositions are hard for us to remember and get right. We convulse our tutor in laughter as we tell her, in Bosnian, about having guests za dinner.
I only wish, when we were having guests na dinner, that we were in Phoenix and could get dessert from the bakery where our niece works.